Pumping unit for liquids

ABSTRACT

A pump is mounted in a housing, and also mounted in the housing is an electromotor which drives the pump. The electromotor has a stationary shaft, a sleeve which surrounds the shaft and is turnable relative to the same, being journalled thereon, an armature which is mounted on the sleeve and a collector which is also mounted on the sleeve. This arrangement facilitates the lubrication of the movable components of the electromotor as compared with constructions wherein the collector and armature are mounted directly on the shaft and it also provides for a more rigid construction.

United States Patent Fussner et a1.

[ July 29, 1975 [5 PUMPING UNIT FOR LIQUIDS 3,433,163 3/1969 Sheets 61a1 417/366 I 3,521,978 7/1970 Enemark 417/423 R [751 lnvemors- PaulFume, Smdelfingen, 3,754,844 8/1973 Nusser et a1. 417/423 HermannNusser, Asperg, both of Germany FOREIGN PATENTS OR APPLICATIONS1,041,153 5/1953 France 417/423 [73] Asslgnee: BSch Stuttgart 949,0702/1964 United Kingdom 417/423 Germany 22 Filed; Jam 11 1974 PrimaryExaminer-C. I. I-lusar Attorney, Agent, or FirmMichael S. Striker [21]Appl. No.: 432,741

[57] ABSTRACT [30] Foreign Application Priority Data A pump is mountedin a housing, and also mounted in Mar. 10, 1973 Germany 2312024 thehousing is an electromotor which drives the P p- The electromotor has astationary shaft, a sleeve 2 s C] H 417 423 417 3 310 7 which surroundsthe shaft and is turnable relative to 51 Int. Cl. F04b 17/00 the Same,bein'gjoumalled thereon, an armature which [58] Field f Search u 7 2366, 3 is mounted on the sleeve and a collector which is also 310/43 7mounted on the sleeve. This arrangement facilitates the lubrication ofthe movable components of the [56] References Cited electromotor ascompared with constructions wherein UNITED STATES PATENTS the collectorand armature are mounted directly on the shaft and It also provldes fora more r1g1d con- 2,649,048 8/1953 Pezzlllo et al 417/423 R Struction3,115,839 12/1963 Pollak et a1 417/368 3,175,758 3/1965 Dirk 417/366 7Claims, 2 Drawing Figures 6 19 37 1S 0 sbL Q PATENTEDJuL29|s7s 3. 897,179

SHEET 1 Fig. I

PATENTEDJULZQIHYS 3,897, 179

SHEET 2 PUMPING UNIT FOR LIQUIDS BACKGROUND OF THE INVENTION The presentinvention relates generally to apumping unit for liquids, and moreparticularly to a pumping unit which is particularly suitable for liquidfuels, such as a fuel pump in an automotive vehicle.

Units of the type in question are already known. Generally speaking theyutilize a housing. a pump located in the housing, and an electromotorwhich is also located in the housing and drives the pump. One prior-artconstruction of the type here in question has a shaft that isstationarily mounted in the housing and on which the armature of theelectromotor is directly journalled. Experience has shown, however, thatwith this prior art construction the lubrication of the rotatingcomponent leaves much to be desired and that the armature as a whole isnot as resistant to deformation as is desirable.

SUMMARY OF THE INVENTION Accordingly, it is an object of the presentinvention to overcome the disadvantages of the prior art.

More particularly, it is an object of the present invention to provide apumping units of the type identified above wherein the armature isparticularly strong and resistant to deformation and wherein the problemof lubricating the rotary components finds an optimum solution.

In keeping with the above objects and with others which will becomeapparent hereafter, one feature of the invention resides, in a pumpingunit for liquids, especially for liquid fuels, in a combination whichcomprises a housing, a pump in the housing, and an electromotor also inthe housing and connected with the pump for driving the same. Theelectromotor comprises a stationary shaft, a sleeve surrounding theshaft and being turnable relative to the same, an armature mounted onthe sleeve, and a collector also mounted on the sleeve.

The construction according to the present invention has the advantage offacilitating greatly the lubrication of the rotary components as willbecome evident from the detailed description of the invention andfurthermore, provides a construction of the armature which is ratherstrong and resistant to flexing and other deformation, because thesleeve on which the armature is mounted is, of course, very resistant tosuch deforma tion.

The novel features which are considered as characteristic for theinvention are set forth in particular in the appended claims. Theinvention itself, however, both as to its construction and its method ofoperation, together with additional objects and advantages thereof, willbe best understood from the following description of specificembodiments when read in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is an axial section through aunit according to the present invention; and

FIG. 2 is a fragmentary section through the armature of the unit in FIG.1.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Discussing now the drawing indetail, wherein a single embodiment has been shown by way of example InFIGS.,.1 .and 2, it will be seen that the novel pumping unit accordingto the present, invention has an elongated housing 1 which is ofapproximately cup-shaped configuration and has an end that is closed bymeans of a cover 2. A portion 3 is mounted on the inner side of thecover 2 and formed with a bearing seat 4 for a shaft 5 which extendsthrough the entire housing 1. At the other end of the housing the shaft5 is journalled in a disc 6 which is located adjacent the transverse endwall of the housing where the latter continuously converges to form aninlet 7 for the liquid to be pumped. The outlet for the pumped liquid isidentified with reference numeral 8 and is provided at the cover 2.

As FIG. 1 shows most clearly, the outlet 8 is provided with a one-wayvalve 10 which is biased by a spring 9 and cooperates with a valve seat11, which is formed by the element 3. The latter is provided with a bore12 which is closed by the one-way valve 10.

Mounted approximately midway in the housing I is the armature 13. Unlikeconventional constructions of this type, the armature 13 of theelectromotor 14 is not mounted directly on the shaft 5. Instead, thearmature 13 is mounted on a support sleeve 15 in form of an elongatedtube which is provided with a constant outer diameter over its entirelength. The inner diameter of the sleeve 15 is enlarged cylindrically at16 and 17, that is at each end of the sleeve 15. These enlargements 16and 17 each accommodate a journal 18 and 19, respectively, which arepressfitted in the respective enlargements. It is currently preferredthat the journals l8 and 19 be of a sintered material, for instance,sintered metal or the like. The inner diameters of the journals l8 and19 is somewhat smaller than the inner diameter of the sleeve 15 wherethe latter is not provided with the enlargements 16 and 17. This meansthat the sleeve 15 is in contact with the shaft 5 only by means of thejournals l8 and 19; in the axial space intermediate the journals 18 and19 there is no contact between sleeve 15 and shaft 5, so that theselatter two elements define with one another a slight gap which caneither be filled by a lubricant or through which lubricant can becirculated which is supplied through the porous sintermaterial journalsl8 and 19.

The armature 13 is mounted on the sleeve 15 by first pressing a stack orpackage 20 of lamellae so that it is located approximately midwaybetween the ends of the sleeve 15. To the right of this package 20 (asseen in FIG. 2) is a short sleeve 21 of synthetic plastic material,whereas to the left of it there is an elongated sleeve or bushing 22which extends close to the associated end of the sleeve 15 and isprovided with a shoulder 23 adjacent which there is located a couplingelement 24 with a groove 25. These components are integrated with thesleeve 22. Accommodated in grooves so as to be insulated between thelamellae of the package 20 are copper windings which are entirelyconventional and whose ends 26 lead to a collector 27 which ispressfitted onto the right-end portion of the sleeve 15. The entirepackage 20 is encapsulated in a layer 28 of synthetic plastic materialwhich can be sprayed onto it or molded (e.g. injection molded) about it.The collector 27 has a synthetic plastic sleeve 29 which is press-fittedonto the sleeve 15 and in which the collector sleeve 30 is anchored. Thecollector 27 faces the cover 2.

A rolled sheet-metal member 31, which is rolled to form a tubularconfiguration extends between the element 3 and the disc 6; it is ofmagnetically conductive material and has connected to it the permanentmagnets 32 of the electromotor 14. The element 3 is formed with radialrecesses 33 which accommodate carbon brushes 34. Springs 35 push thesecarbon brushes against the collector 27.

The groove 25 of the sleeve 22 is connected with an impeller 36 of thepump. The impeller is located between the disc 6 and a further disc 37which is connected with the disc 6 by means of screws 38 and anintermediate member 39. The impeller is constructed in known manner andits particular construction is not of importance for the purposes of thepresent invention and known per se to those skilled in the art. A slot6' is formed in the disc 6 which communicates with the pumping chambersof the impeller 36. It will be appreciated when the impeller 36 isrotated by the electromotor 14, it creates suction in the inlet 7,drawing in the liquid to be pumped, and expelling it along the armatureto the outlet 8 where it passes the one-way valve and advances to theuser. The valve 10 of course prevents a return flow of the pressurizedliquid I into the unit.

It will be understood that each of the elements described above, or twoor more together, may also find a useful application in other types ofconstructions differing from the types described above.

While the invention has been illustrated and described as embodied in apumping unit for liquids, it is not intended to be limited to thedetails shown, since various modifications and structural changes may bemade without departing in any way from the spirit of the presentinvention.

Without further analysis, the foregoing will so fully reveal the gist ofthe present invention that others can, by applying current knowledge,readily adapt it for various applications without omitting features thatfrom the standpoint of prior art, fairly constitute essentialcharacteristics of the generic or specific aspects of this inventionand, therefore, such adaptations should and are intended to becomprehended within the meaning and range of equivalence of thefollowing claims.

What is claimed as new and desired to be protected by Letters Patent isset forth in the appended claims:

1. ln a pumping unit for liquids, particularly for liquid fuels, acombination comprising a housing; a pump in said housing; anelectromotor in said housing and connected with said pump for drivingthe same, said electromotor comprising a stationary shaft, a sleevesurrounding said shaft and being turnable relative to the same, saidsleeve having opposite axial end portions, each provided with a recessin an inner circumferential surface of said sleeve, an armature mountedon said sleeve, and a collector also mounted on said sleeve; and a pairof journals, each received in one of said recesses and journalling saidsleeve on said shaft, said journals being of sintered material and beingpress-fitted into the respective recess and having respective innerdiameters slightly smaller than the inner diameter of said sleeve sothat the latter surrounds said shaft with a slight clearance.

2. A combination as defined in claim 1, said sleeve being of constantouter diameter, and said armature comprising a stack of lamellae whichis press-fitted onto said sleeve exteriorly of the latter.

3. A combination as defined in claim 2, wherein said collector ispress-fitted onto said sleeve exteriorly of the latter.

4. A combination as defined in claim 2, wherein said collector ispress-fitted onto said sleeve exteriorly of the latter and adjacent oneaxial end of said armature.

5. In a pumping unit for liquids, particularly for liquid fuels, acombination comprising a housing; a pump having a rotary impeller insaid housing; an electromotor in said housing and connected with saidpump for driving the same, said electromotor comprising a stationaryshaft, a sleeve of constant outer diameter surrounding said shaft andbeing turnable relative to the same, an armature including a stack oflamellae which is pressfitted onto said sleeve exteriorly of the latter,a collector also press-fitted onto said sleeve exteriorly of the latterand adjacent one axial end of said armature; and a bushing press-fittedonto said sleeve adjacent an opposite axial end of said armature andprovided with a groove for mutual engagement with said impeller.

6. A combination as defined in claim 5, wherein said bushing is ofsynthetic plastic material.

7. In a pumping unit for liquids, particularly for liquid fuels, acombination comprising a housing; a pump in saidhousing; an electromotorin said housing and connected with said pump for driving the same, saidelectromotor comprising a stationary shaft of constant diameter, asleeve surrounding said shaft and being turnable relative to the same,said sleeve having opposite end portions and being of relatively largerdiameter than said shaft so as to define an axial space therewith, anarmature mounted on said sleeve, and a collector also mounted on saidsleeve; and a pair of journals of porous sinter material provided onsaid opposite end portions and journalling said sleeve on said shaft andcommunicating with said axial space, so that the pumped liquid canpermeate through said journals into said axial space and lubricate saidturnable sleeve.

1. In a pumping unit for liquids, particularly for liquid fuels, acombination comprising a housing; a pump in said housing; anelectromotor in said housing and connected with said pump for drivingthe same, said electromotor comprising a stationary shaft, a sleevesurrounding said shaft and being turnable relative to the same, saidsleeve having opposite axial end portions, each provided with a recessin an inner circumferential surface of said sleeve, an armature mountedon said sleeve, and a collector also mounted on said sleeve; and a pairof journals, each received in one of said recesses and journalling saidsleeve on said shaft, said journals being of sintered material and beingpress-fitted into the respective recess and having respective innerdiameters slightly smaller than the inner diameter of said sleeve sothat the latter surrounds said shaft with a slight clearance.
 2. Acombination as defined in claim 1, said sleeve being of constant outerdiameter, and said armature comprising a stack of lamellae which ispress-fitted onto said sleeve exteriorly of the latter.
 3. A combinationas defined in claim 2, wherein said collector is press-fitted onto saidsleeve exteriorly of the latter.
 4. A combination as defined in claim 2,wherein said collector is press-fitted onto said sleeve exteriorly ofthe latter and adjacent one axial end of said armature.
 5. In a pumpingunit for liquids, particularly for liquid fuels, a combinationcomprising a housing; a pump having a rotary impeller in said housing;an electromotor in said housing and connected with said pump for drivingthe same, said electromotor comprising a stationary shaft, a sleeve ofconstant outer diameter surrounding said shaft and being turnablerelative to the same, an armature including a stack of lamellae which ispress-fitted onto said sleeve exteriorly of the latter, a colLector alsopress-fitted onto said sleeve exteriorly of the latter and adjacent oneaxial end of said armature; and a bushing press-fitted onto said sleeveadjacent an opposite axial end of said armature and provided with agroove for mutual engagement with said impeller.
 6. A combination asdefined in claim 5, wherein said bushing is of synthetic plasticmaterial.
 7. In a pumping unit for liquids, particularly for liquidfuels, a combination comprising a housing; a pump in said housing; anelectromotor in said housing and connected with said pump for drivingthe same, said electromotor comprising a stationary shaft of constantdiameter, a sleeve surrounding said shaft and being turnable relative tothe same, said sleeve having opposite end portions and being ofrelatively larger diameter than said shaft so as to define an axialspace therewith, an armature mounted on said sleeve, and a collectoralso mounted on said sleeve; and a pair of journals of porous sintermaterial provided on said opposite end portions and journalling saidsleeve on said shaft and communicating with said axial space, so thatthe pumped liquid can permeate through said journals into said axialspace and lubricate said turnable sleeve.